WIRE AND DISCONNECT SIZING

The MX60 has a 60 amp current output limit (default) and is listed to operate continuously at 60 amps depending on the nominal PV array voltage and the nominal battery voltage. There is no 80% de-rating as required by the NEC for fuses, conductors, and most circuit breakers.

The MX60 is a buck type converter and cannot boost the output current when the PV array peak power point voltage is at or below the battery voltage as may happen on hot days in 24 VDC PV and a 24 VDC battery system or a 48 VDC PV and a 48 VDC battery system.

To meet minimum NEC requirements (NEC 310.15, 690.8, 9), the output conductor should have an ampacity of 75 amps after any temperature and conduit fi ll corrections. This would normally indicate that the output conductors be 4 AWG, but a larger size may be required if there are temperature and/or conduit fi ll corrections required. With an output conductor rated at 75 amps (1.25 X the continuous output current), the OutBack OBDC-60 breaker—rated for continuous 100% duty at 60 amps —can be used to provide the code-required disconnect and output circuit over current protection.

The PV array output connected to the MX60 input may be as high 60 amps, but at this current level, there is very little (if any) current boosting or maximum power-point tracking due to the

60-amp output current limit. Additionally, the input current may exceed 60 amps on bright sunny days and any excess power would be lost. The size and ampacity of the input conductors must be selected to handle 1.56 times the short-circuit current of the PV array. Any disconnect or circuit breaker connected to the input conductors must also be rated at 1.56* times the short-circuit current for the PV array unless the breaker is rated for 100% duty in its enclosure. If that is the case, the circuit breaker may be rated at 1.25 times the PV array short-circuit current. OutBack OBDC-XX breakers are 100% duty rated breakers.

In terms of NEC compliance and the MX60’s 60-amp output rating, the largest PV array it can con- nect to should have a rated short-circuit current of 48 amps. This meets NEC requirements and allows the MX60 to perform maximum power-point tracking functions. The following charts show maximum distance in feet of various gauge two-conductor copper wire from the PV array to the MX60 with a 1.5% maximum voltage drop. Temperature and conduit fi ll corrections may

be required.

*UL requires Isc to be multiplied by 125% for the conductor rating

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Outback Power Systems MX60 user manual Wire and Disconnect Sizing
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MX60 specifications

The Outback Power Systems MX60 is a state-of-the-art solar charge controller designed for off-grid and grid-tied systems, providing users with cutting-edge technology and efficiency in managing their solar energy resources. This device stands out in the renewable energy market due to its versatile features, robust performance, and ease of use.

One of the main features of the MX60 is its high-efficiency MPPT (Maximum Power Point Tracking) technology. This advanced technology optimizes the energy harvested from solar panels by adjusting the electrical operating point of the modules, allowing the system to extract the maximum available power. The MX60 can handle a considerable input voltage of up to 150 volts and offers a maximum output current of 60 amps, making it suitable for both small and large-scale installations.

The MX60’s robust architecture ensures its durability in harsh environmental conditions. With an operating temperature range of -40°F to 176°F, the charge controller performs reliably in varied climatic conditions, whether in extreme heat or bitter cold. This makes it an ideal choice for remote locations and rugged terrains where traditional power sources might be unreliable or unavailable.

An intuitive LCD interface equipped with a user-friendly display allows for easy monitoring and configuration. Users can track real-time performance metrics, including solar array voltage, output current, battery voltage, and charging status. The device is also equipped with advanced programmable settings, offering users complete control over charging parameters and battery maintenance.

Moreover, the MX60 incorporates essential safety features, including over-voltage and over-current protection, reverse polarity protection, and temperature compensation. Such safety measures are crucial in preventing damages to both the controller and the connected battery system.

The MX60 is compatible with various battery types, including Flooded, AGM, Gel, and Lithium, providing flexibility in energy storage options. It seamlessly integrates with Outback's Radian inverter systems, facilitating a comprehensive energy management solution for residential and commercial applications.

In summary, the Outback Power Systems MX60 is an exceptional choice for those looking for a reliable and efficient solar charge controller. Its combination of advanced technology, robust construction, and user-friendly features makes it an essential component for anyone interested in harnessing the power of solar energy.
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